Process for the treatment of rubber



No Drawing. isp nan'oiilaiea March 5", 1923, seriaif'mueaenza aaa inpreeti r itainMarIeh'11,3922.

. self-vulcanizingrubber solutions Vulcanized by any of theusual or suitable processes Patented 6, 192 6rl rRocEss FOR THE: "rREAairiEn-T or R-u isER:

This invention relates to the treatment of which normally result in a gel, such, for instance, by the Peachey process, by sulphur chloride and by sulphur or the like; Such solutions possess the disadvantage of setting to gels comparatively rapidly, which prevents their further use as solutions for dipping, moulding, cementing or the like.

I have found that vulcanized doughs can be produced by treating a rubber solution to form agelling solution as above stated, and then mixing with said solution, before it gels, a suitable proportion of a rubber precipitantsuch as acetone, alcohol or the like which precipitates, a vulcanized dough,

. moreover, by combining a rubber solvent,

such as benzine, naphtha'or the like in suitable proportion with the precipitant, and

mixing the combined'solvent and precipitantwith the treatedsolution before it gels, I find that: the gelling action is completely arrested,.no precipitation takes place, and a stable and mobile non-gel. liquid, prop erly vulcanized, is the resultant. These astonishing results were not to be anticipated because the addition of'a rubber pre- 'cipitant to ordinary non-vulcanized rubber solutions precipitatesa plain or pure rub ber, and. theaddition of solvent by'itself to a self-vulcanizing solution, as herein specified, prior to gelling, ,does not prevent gelling'but merely retards it. Q

The method of procedure is jas follows A solution "of rubber and sulphur is formedin any usual manner, so that, ordinarily, gelling would take place within-a period of minutes; the solution is,'however, stirred until it thickens towards the gelling precipitant such as acetone in suflicient quancity to bring down a precipitate; thisis vulcanized rubber dough containing a compara-i tively small percentage of solvent. Such V dough can be moulded, pressed or otherwise worked and then dried,ffor the production of completely curedrubber articles, The

precipitant so added is in excess of the--- V solvent present in the gelling solution in precipitation, or .non tack'y by an excess of.

order toproduce the dough, but the dough can be made sticky or adhesive by an excess of benzine or thelike in the solution after liquid for use at anytime. V V o a 'In the" modification whereby there is proplete separation if necessary;

* IQRDYC B ARI Y IQN Si qr QHDPN Ensure precipitant. The dough may duced a stable non-gelling vulcanized solution, I' make a mixture of acetone and benezine (or equivalents) and. prefer to pour the sel'E-vulcanizing rubber solution into this If carefully *stirredin, no precipitation takes place but thegelling action isstopped,

and the soluti'on remains liquid; when dried f out this gives a product. of vulcanized rub ber.

formationofclots/ keptin the The acetone and "benzine could be; poured into thesolution, but I find there} verse way to be effective in preventing'the As an example of the production :of V111; camzed doughs and. stablelliquids accord ing to my invention, lymph- -c. c. of

standard l2 rubberlsolution, and [cured it" by the Peachey process, whereby the S0111: -i" 1 tion was saturated with sulphuretted hywas added, containing sufficient sulphur "drogen, following which 10 c. {of benz ne condition of cure of the resultant product,

I added suflicient acetone to bring down the dough precipitate; about 150 c; c. was em-- ployed. 200 c; clean be used toensurecorn I iTaking the same quantity and carefully and s1owly"into 1()0 c.' c. of a inixi li r o self-vulcanizing solution, I poureditfvery" -90,

ture of one, part of acetone and two of be lzine, stirring the while, ,and the resultant was the stable vulcanized so-lution j herein 5 referred to. Ordinary room temperature" r obtained. It is pointed. out thatthe q uan- 'tities hereinbefore mentioned may-bevaried "within a large degree, andd0ughso13solutions, respectively still Tresultybysuch means, vulcanized solutions, for instance of different strengths andqualities may ob;

tained. r

1 The dough may sired result, V

lclaimzf rubber dough' which consists in first treatin a rubber solution to form a self-vulcanize have the addition-offlany fillers, colouring matter and the like, and, can be kneaded, "masticated'. and finally pressedinto shape, and dried 01f to the dc gelling solution, andmixing together said solution, before it setsihto a; gel, andxa' I suitable proportion of arubber precipitant whereupon a vulcanized dough is precipitated out, substantially as herein described.

2. The method of treating rubber which comprises treating a solution thereof with a quantity of hydrogen sulfid and sulfur dioxide sufficient'to' cause jellation thereof .in

In testimony whereof I have afjxed iny signature hereto this 2nd clay of February, 1923.

FORDYOE. CHARLES: JONES. 

